class Solution {
    public boolean isSubtree(TreeNode root, TreeNode subRoot) {
        if(root==null){
            return false;
        }
        if(isSameTree(root,subRoot)){
            return true;
        }
        if(isSubtree(root.left,subRoot)){
            return true;
        }
         if(isSubtree(root.right,subRoot)){
            return true;
        }
        return false;



    }
     public boolean isSameTree(TreeNode p, TreeNode q) {
        if(p==null&&q!=null||p!=null&&q==null){
            return false;

        }
        if(p==null&&q==null){
            return true;
        }
        if(p.val!=q.val){
            return false;
        }
       return isSameTree(p.left,q.left)&&isSameTree(p.right,q.right);

    }
}